22 PROCEEDINGS OF THE NATIONAL MUSEUM vol. GG 



Occurrence. — MidtUe or lower Miocene: In flood-wash. 1 mile south 

 of Brasso, Trinidad. British West Indies. 



DRILLIA NITRINA, new species 



Plate 3, fig. 3 



Shell small, rather stout, semiporcellaneous, strongly axially 

 sculptured, six whorled including one nuclear whorl. Nucleus large, 

 smooth and bulbous. Postnuclear whorls slightly inflated: suture 

 distinct, shallowly grooved, with a low poorly defined band below. 

 Anal fasciole moderately wide, not depressed, undulating. Sculp- 

 ture consists of about eleven, vertical ribs extending with equal 

 strength across the whorl, separated by rounded intersj^aces of about 

 equal width; on the body whorl, the ribs become obsolete on reach- 

 ing the canal. Spirally sculptured on the later whorls, between the 

 axials, with five striae separated by flat rather wide bands; on the 

 body whorl and overrunning the canal, there are 15 of these bands 

 separated by wider interspaces, especially those over the canal. 

 Outer lip broken away. Pillar smooth. Siphonal canal short and 

 anteriorly, dextrally twisted. 



Dimensions: Type (U. S. Xat. Mus. Cat. No. 352637) measures: 

 Altitude 6.5 mm. ; greatest diameter 2.5 mm. 



Occurrence. — Middle or lower Miocene : In flood-wash, 1 mile 

 south of Brasso, Trinidad, British West Indies. 



DRILLIA INADRINA. new species 



Plate 3, fig. 6 



Shell small, moderately slender, porcellaneous, strongly axially 

 sculptured and consists of one and one-half nuclear and six post- 

 nuclear whorls. Suture closely appressed and wavy — the scallops 

 entering the interaxial hollows. Nucleus quite small, smooth and 

 inflated. Postnuclear whorls sculptured with strong, semiacute, 

 widely spaced, sigmoid ribs (eight on the penult whorl), strongest 

 anteriorly and weakest posteriorly, extending from just in front of 

 the sutural margin forward to the following suture; the axials on 

 each whorl are opposite the wide, concave, interaxial spaces on the 

 adjoining whorl. Over the base, the axials gradually diminish 

 in size and become obsolete at the juncture of the anterior canal. 

 In front of the suture and between the axials, there is a slightly 

 raised area. Whorls without spiral sculpture except for a single, 

 indistinct stria midway between the sutures. Outer lip sharp. 

 Inner lip smooth, the exterior margin overlapping the canal; canal 

 short, arcuate and incurved. The siphonal fasciole is bounded above 

 by a spiral thread. 



